The present invention relates to methods and apparatus for providing touch sensitive displays, such as liquid crystal displays, organic light emitting diode displays, etc.
The display market is eager for displays that offer touch sensing capability—and the market size for displays with touch functionality is expected to grow tremendously in the coming years. As a result, many companies have researched a variety of sensing techniques, including resistive, projected capacitive, infrared, etc. While many of these techniques result in reasonable touch capability, each technique carries some performance disadvantage for specific applications, and nearly all result in significant added cost to the manufacture of each display.
In terms of performance, the basic metrics for touch sensitive displays are the accurate sensing of a touch event and the determination of the precise location of the touch event on the touch/display window. Many secondary attributes are becoming important for added functionality, including flexibility in sensing various touching implements beyond the human finger, such as a pen, stylus, etc., the ability to sense multiple, simultaneous touch events, location resolution, and the ability to distinguish false touches (hovering, or environmental disturbances).
As touch sensitive displays are gaining wider use in mobile device applications, the overall thickness and weight of the touch sensitive display are becoming more important metrics for commercial viability. When such additional criteria are taken into consideration, very few sensor technologies stand out.
Accordingly, there are needs in the art for new methods and apparatus for providing thinner and lighter touch sensitive displays, with low cost, tight manufacturing tolerances, and ease of manufacture being related goals.